Centella asiatica, often listed as “cica” on product labels, is a plant extract that primarily boosts collagen production, calms inflammation, and strengthens the skin’s protective barrier. It’s one of the more well-researched botanical ingredients in skincare, with studies spanning wound healing, hydration, and scar prevention. Here’s what it actually does at the skin level and how to get the most from it.
How Centella Builds Collagen
Centella’s headline benefit is its ability to increase collagen production, and this is where the research is strongest. The extract works by stimulating fibroblasts, the cells in your dermis responsible for producing collagen and other structural proteins. Studies on human dermal fibroblasts show that centella increases both type I collagen (the most abundant type in skin, responsible for firmness) and type III collagen (which provides elasticity and is critical during wound repair). It also boosts fibronectin, a protein that acts as scaffolding for new tissue.
What makes this practically meaningful: the new collagen isn’t just more abundant, it’s also stronger. Research shows that centella’s active compounds increase the tensile strength of newly formed skin, meaning the repaired tissue is more resilient. This is why centella has a long history in wound care products. A prescription ointment called Madecassol, used in parts of Europe and Asia, contains centella triterpenes specifically for healing skin ulcers and wounds.
The Four Compounds That Do the Work
Centella contains four key active compounds, all triterpenes: asiaticoside, madecassoside, asiatic acid, and madecassic acid. They don’t all do the same thing. Asiatic acid is the primary driver of collagen synthesis in human fibroblasts. Asiaticoside stimulates type I collagen production and also promotes blood vessel formation, improving circulation to healing skin. Madecassoside stimulates type III collagen and has shown particular benefit in burn wound healing by enhancing antioxidant activity at the wound site.
Asiaticoside also appears to be the biggest contributor to centella’s antioxidant activity, helping neutralize free radicals that break down collagen and accelerate aging. Together, these four compounds also stimulate the production of hyaluronic acid and other glycosaminoglycans, molecules that hold moisture in your skin’s deeper layers.
Soothing Inflammation and Redness
Centella reduces visible redness and irritation by dialing down the inflammatory signals your skin cells produce. Research shows it inhibits pro-inflammatory molecules including TNF-alpha and IL-6, two of the key drivers of redness, swelling, and sensitivity in skin. This makes it particularly useful if you’re dealing with reactive or easily irritated skin, or if you’re using stronger actives like retinol or benzoyl peroxide that can trigger inflammation on their own.
In one clinical study, a gel containing purified centella compounds was applied to skin after laser resurfacing. The treated side showed significantly faster resolution of redness, with erythema subsiding by day 7 compared to day 28 on the placebo side. That’s a meaningful difference for anyone dealing with post-procedure redness or the kind of lingering irritation that comes with aggressive treatments.
Barrier Repair and Hydration
Your skin’s outermost layer acts as a barrier that locks in moisture and keeps irritants out. When that barrier is compromised, you lose water through the skin faster than normal, a measurement called transepidermal water loss (TEWL). Centella helps restore this barrier. In a clinical study measuring skin hydration over 24 hours, a moisturizer containing centella stem cell extract reduced water loss by up to 52% compared to baseline after barrier disruption. The improvement held at the 24-hour mark, with a 48% reduction still in place.
A 5% centella extract in an oil-in-water emulsion significantly improved hydration of the outermost skin layer compared to other formulation types at the same concentration. This suggests that both the concentration and the delivery vehicle matter when choosing a centella product.
Scar Prevention and Healing
Centella’s combination of collagen stimulation, anti-inflammatory action, and tissue-strengthening effects makes it effective for minimizing scars. The key mechanism is that it regulates how collagen is deposited during healing. Uncontrolled or excessive collagen production leads to raised, hypertrophic scars. Centella promotes organized collagen synthesis and cross-linking, which results in flatter, smoother scar tissue.
In a clinical trial, a cream containing 7% centella extract was applied to donor scar sites and compared against a placebo. The centella-treated areas showed improved healing outcomes. The extract also promotes cell migration from surrounding healthy tissue into the wound, speeding up the overall repair process. For post-acne marks specifically, centella isn’t a direct acne treatment, but its ability to calm redness and support organized healing makes it useful for reducing the discoloration and texture changes that acne leaves behind.
Pairing Centella With Other Ingredients
Centella plays well with most common skincare actives, which is one reason it appears in so many formulations. With niacinamide, you get overlapping soothing and antioxidant benefits, plus niacinamide’s ability to improve oil quality and minimize pore appearance. With vitamin C, the pairing creates a strong antioxidant and collagen-supporting combination, since both ingredients protect skin architecture through slightly different pathways.
Where centella really shines as a partner ingredient is alongside potentially irritating actives. If retinol or benzoyl peroxide causes redness and flaking, using a centella-based moisturizer or serum in the same routine can help keep irritation manageable. It won’t interfere with how those actives work, but it will reduce the visible side effects that make people abandon their routines.
Concentrations and What to Look For
Clinical studies have used centella extract at concentrations ranging from about 1% to 7%, with most falling in the 1% to 5% range. A 5% extract in an emulsion-based product showed clear hydration benefits. Lower concentrations around 1% have demonstrated wound healing effects in animal models. Products listing “Centella asiatica extract,” “madecassoside,” or “asiaticoside” near the top of their ingredient list generally contain meaningful amounts.
You’ll also see “TECA” (titrated extract of Centella asiatica) on some products, which refers to a standardized blend of the three most active triterpenes: asiatic acid, madecassic acid, and asiaticoside. TECA formulations have the most consistent research behind them because the active compound ratios are controlled.
Side Effects and Skin Tolerance
Centella is one of the gentler active ingredients available. In a prospective study on subjects with sensitive skin using a centella-based product, the most common side effects were minor breakouts (new papules or comedones on the cheeks and jawline), and all resolved within a week without treatment. One subject reported temporary tingling that lasted two to three minutes. No serious adverse events were recorded. Allergic contact dermatitis to centella has been reported in the literature but is rare. If you have known sensitivity to plants in the Apiaceae family (which includes carrots, celery, and parsley), it’s worth patch testing first, since centella belongs to the same botanical family.